I'm mulling the 5W30. I wanna say they use more viscosity improver to do this than 5W20. It used to be sold as STP - maybe still is. polyisobutylene I think. Anyway, keep this in mind in your research. The part here I'm really wondering is what's the impact on intake valve deposits? I'm wary that that aspect may end up trumping all other considerations on our engines.
The 5W-30 should be no problem for you for the spring/summer oil change interval.
There are some oils on the market (mostly high-end, group 4/5 base stock, 'boutique oils') which use NO viscosity index improvers
whatsoever (except for the most 'extreme' range viscosity spreads, like; 0W-40/5W-50/10W-60, etc.), as they get their multi-viscosity 'spread' from their superior base stocks, while still maintaining an above average viscosity index.
Any name brand modern oil out there (especially the ones labeled as "Synthetic") which DO use V.I. improvers now use high grade, SUPERIOR chemistry/composition VIIs which do NOT shear, and break down to form deposits like the ones of yesteryear (or at least NOT as radically/quickly as the ancient VIIs), and they are NOT using the same chemistry as in STP!
The only aspects of any oil which would effect modern DI/turbo power trains negatively (as far as intake valve deposits go) are it's actual
volatility, and having a SKY HIGH PPM additive package,
especially the ZDDP content, and/or SAPS (sulfated ash, phosphorus, and sulfur) and high calcium, magnesium, and/or boron detergent/dispersant/acid neutralizing packages.
(Which sadly, MANY of the 'boutique' oils like Red Line, Motul 300V, Millers NT, Torco SR-5, JGD, MPT 30K, etc. have as a matter of course, and why I am still a little reluctant to use them for the spring oil change, as much as I want to, and am
tempted to try them.)
There should be NO PROBLEMS WHATSOEVER with ANY of this when using an 'on the shelf' synthetic at Wal Mart/Vato Zone/Advance/Peppies/etc. in 0W-20, 5W-20, or 5W-30 viscosities, since they have additive levels set by the API/SAE so as NOT to be deposit forming
even if the oil gets past the rings, or valve seals, and into the combustion chamber.
Most also have much lower volatility rates than those even required by the latest, and most stringent tests to get those current API/SAE/ACEA specs.